1. Field of the Invention
A musical scale selector for a musical keyboard allows different musical scales to be sounded on the same sequence of instrument digitals, thereby changing the keyboard fingering of musical compositions. This device eases the playing of music if the music is reprinted in an easier notation.
A key signature actuator for a musical keyboard eases playing from musical compositions written with difficult key signatures without reprinting the music, by changing the fingering of the musical compositions.
2. Description of the Prior Art
The traditional way of writing Western music is to represent the seven tones of a C major diatonic scale by notes on five-line staffs. Interspersed notes of the chromatic scale are referred to the notes of the basic diatonic scale by means of sharp or flat symbols which serve as corrections to the basic diatonic notes. Thus a chromatic note intermediate to the C and D note is represented by C sharp or D flat.
For a diatonic musical composition to be written without the use of sharp or flat symbols, it must be written in the key of C. Such a restriction would severely limit a modern composer, for he probably wants to base his musical composition on a tonic above or below a standard C pitch. This would be no problem for singers or for musical instruments having uniform pitch changers, but many musical instruments do not have such pitch changers. So composers and their publishers resort to a rather unsatisfactory method for changing the absolute pitch of their diatonic scale-they start the major mode of the diatonic scale on some other note than C. This method requires that one or more of the seven diatonic notes be corrected by means of a sharp or flat symbol. The composer finds it convenient to specify the diatonic note corrections by means of a key signature that is placed at the front of each line of written music. Key signatures greatly reduce the effort needed to write modern music in other keys than C, and to understand the written music.
The traditional musical keyboard was structured so as to facilitate performance of music in the major diatonic key of C. As early as the fifteenth century, keyboard instruments had seven front digitals to play the diatonic scale and five back digitals per octave span to play other notes of the chromatic scale. The major mode of a diatonic scale, starting with a C note, starts on a C front digital. The succeeding D,E,F,G,A,B notes of the diatonic scale are played on the succeeding D,E,F,G,A,B front digitals. The notes of written music can thus be interpreted as instructions to play particular digitals of the keyboard, each digital of the keyboard being identified by a note in the written music and serving to identify that musical note. This arrangement had the singular advantage that the most commonly used notes were played on the wide front digitals of the keyboard. At that time there was a one-to-one correspondence between the key in which music was written and played and the pitch of its diatonic scale as sounded.
Many modern keyboards are equipped with uniform pitch changers, which raise or lower the output tones from all the different digitals of the keyboard by the same musical interval. Since this type of transformation does not change the relative musical intervals between the different notes of a musical composition, it is recognized as the same musical composition sounded at a different overall pitch. Thus with many modern keyboards there is no longer a one-to-one correspondence between the key in which music is written and played and the pitch of its diatonic scale as sounded.
The note corrections specified by a key signature require playing of the back digitals. This detracts from the previous virtue of the traditional keyboard, of providing wide front digitals for the most commonly used notes. Furthermore, the ordinary keyboard player has difficulty remembering and playing all the sharps and flats called for in the fourteen key signatures. Music publishers have rewritten some of the older music with easier key signatures, but the rewritten music is usually harder to sing and it usually does not sound as good as when it was played in its original key. It is possible to reprint all music in the key of C for the benefit of musicians having uniform pitch changers, but the reprinted music would not be satisfactory for playing on instruments without uniform pitch changers, and publication of music written in different keys increases the logistic problem of distributing the written music.
To alleviate these difficulties, a keyboard instrument can be provided with a device to physically actuate the note corrections specified in the key signature. Such a device, which I call a key signature actuator, was disclosed by Martin Philipps in 1886 (U.S. Pat. Nos. 354,733, 466,907 and 519,071). If, for example, the device was set for a key signature with one sharp, then the F front digital would play not the F tone but the F sharp tone instead, as called out in the key signature.
As opposed to a uniform pitch changer, a key signature actuator changes some of the musical intervals between the tones sounded by a given sequence of digitals. For example, when the F front digital is made to sound the F sharp tone the interdigital musical interval between the E and F digitals is changed from one semitone to two semitones, and the interdigital musical interval between the F and G digitals is changed from two semitones to one semitone. A consequence of this difference between a key signature actuator and a uniform pitch changer is that key signature actuators are generally more difficult to construct, and they are not widely available.
Whereas the function of a uniform pitch changer is to change the overall pitch of the output music away from the pitch of the written music, the function of a key signature actuator is to ease playing from musical compositions written with difficult key signatures without rewriting the music, by changing the keyboard fingering of the musical compositions.
A key signature actuator greatly reduces the mechanical difficulty of playing in other keys than C, because the most frequently used notes are again played on the wide front digital of the keyboard. The mental difficulty of playing music is also reduced, because the musician can play the notes in the body of the written music without regard to its key signature. Unfortunately, partly because of their complexity and expense, key signature actuators are not generally available. If key signature actuators were available commercially, then a musical composition could more generally be published in the musical key in which it sounds best and is most easily sung. This better music could then be played by inexpert players on electronic musical instruments having key signature actuators. More expert musicians having acoustic instruments without either uniform pitch changers or key signature actuators could also play the better music.
Electrical versions of a key signature actuator are described in my U.S. Pat. Nos. 3,986,422, 4,048,893, 4,640,173, and 4,750,399, and my copending application Ser. No. 166,464, U.S. Pat. No. 4,821,619.
In modern musical practice it is common to have a musical keyboard and a sound generator in different places, the keyboard transmitting digital messages to the sound generator on a single pair of twisted wires. When a digital of the keyboard is pressed, a "Note On" message is transmitted in binary code to the sound module, accompanied by a digital identifying number. These messages are used by the sound module to generate a musical tone of the proper pitch. When the keyboard digital is released, a "Note Off" message, accompanied by the digital identifying number, is transmitted to the sound module, and the musical tone is discontinued. Musical instrument manufacturers have established an international standard for such communication, called "Musical Instrument Digital Interface" (MIDI).
My copending patent application Ser. Nos. 015,718 and 058,367 filed 6-5-87 disclose new uses for the MIDI interface whereby MIDI transmission to a sound generator is intercepted and the numbers changed in accordance with a selected key signature, the substituted numbers resulting in automatic actuation of the key signature. When the same musical composition is written in different keys, the key signature actuators allow all diatonic notes to be played on the front digitals of musical keyboards and the non-diatonic notes to be played on the back digitals of the keyboard. Application Ser. No. 058,367 filed Jun. 5, 1987 also causes interleaved whole tone scales to be played by the two rows of front and back digitals. This keyboard arrangement allows a musical composition to be played at all pitches with only two different relative fingerings, depending on whether the composition starts on a front or back digital. This is the best keyboard arrangement when playing from twelve-tone notation, which does not need key signatures.